Steerable medical device and method

ABSTRACT

In various examples, a system includes a steerable medical device including a handle including a longitudinal axis. An elongate shaft extends distally from the handle. The elongate shaft includes a distal tip and a lumen through the elongate shaft. At least four pullwires are disposed within the handle and extending to and anchored proximate the distal tip of the elongate shaft. At least two actuators are associated with the handle. The at least two actuators are operably coupled to the at least four pullwires with actuation of the first actuator causing tension in the first or second pullwire to deflect the distal tip in a first or second tip direction, respectively, and actuation of the second actuator causing tension in the third or fourth pullwire to deflect the distal tip in a third or fourth tip direction, respectively.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of priorityunder 35 U.S.C. § 120 to Scheibe et al., U.S. patent application Ser.No. 15/917,953, filed on Mar. 12, 2018, entitled “STEERABLE MEDICALDEVICE AND METHOD,” which claims the benefit of priority to U.S.Provisional Application Ser. No. 62/471,003, filed on Mar. 14, 2017,entitled “CATHETER STEERING HANDLE,” each of which is incorporated byreference herein in its entirety.

BACKGROUND

The present invention relates to a steerable device, and morespecifically relates to a medical device that is steerable in multipledirections.

In various medical procedures, steerable catheters or other devices canallow for navigation to a location within a patient and/or articulationwithin the patient in order to access the location and/or achieve aparticular orientation or series of orientations within the patient. Inmany cases, such devices include limited degrees of motion, making itdifficult to achieve particular orientations and or locations. In turn,such devices make some medical procedures more difficult than themedical procedures would otherwise be with a device having more degreesof motion.

OVERVIEW

This overview is intended to provide an overview of subject matter ofthe present patent document. It is not intended to provide an exclusiveor exhaustive explanation of the invention. The detailed description isincluded to provide further information about the present patentdocument.

The present inventors have recognized, among other things, that thesubject matter can be used with respect to a medical device withmultidirectional steering capability. In various examples, the presentsubject matter can be used with a device, an apparatus, a system, and/ora method to provide for increased maneuverability within a patient. Thepresent inventors have recognized that the present subject matter can beused to provide a catheter or other medical device with multiple degreesof motion to allow for a tip of the device having a 360-degree range ofdeflection. To better illustrate the apparatuses, systems, and methodsdescribed herein, a non-limiting list of examples is provided here:

Example 1 can include subject matter that can include a steerablemedical device including a handle including a longitudinal axis. Anelongate shaft extends distally from the handle. The elongate shaftincludes a distal tip and a lumen through the elongate shaft. At leastfour pullwires are disposed within the handle and extend to and areanchored proximate the distal tip of the elongate shaft. The at leastfour pullwires include a first pullwire, a second pullwire, a thirdpullwire, and a fourth pullwire. At least two actuators are associatedwith the handle. The at least two actuators include a first actuator anda second actuator. The at least two actuators are operably coupled tothe at least four pullwires. Actuation of the first actuator in a firstactuator direction causes tension in the first pullwire and deflectionof the distal tip in a first tip direction. Actuation of the firstactuator in a second actuator direction causes tension in the secondpullwire and deflection of the distal tip in a second tip directionsubstantially opposite the first tip direction. Actuation of the secondactuator in a first actuator direction causes tension in the thirdpullwire and deflection of the distal tip in a third tip directiondifferent from the first tip direction and the second tip direction.Actuation of the second actuator in a second actuator direction causestension in the fourth pullwire and deflection of the distal tip in afourth tip direction substantially opposite the third tip direction.

In Example 2, the subject matter of Example 1 is optionally configuredsuch that the at least four pullwires extend within the elongate shaftto proximate the distal tip of the elongate shaft.

In Example 3, the subject matter of any one of Examples 1-2 isoptionally configured such that the first actuator is rotatable aboutthe longitudinal axis of the handle.

In Example 4, the subject matter of any one of Examples 1-3 isoptionally configured such that the second actuator is rotatable aboutthe longitudinal axis of the handle.

In Example 5, the subject matter of any one of Examples 1-4 isoptionally configured such that the first actuator and the secondactuator are each independently rotatable about the longitudinal axis ofthe handle.

In Example 6, the subject matter of any one of Examples 1-5 optionallyincludes a first threaded member disposed within the handle and movablewith actuation of the first actuator. The first threaded member isoperably coupled to the first and second pullwires, wherein movement ofthe first threaded member causes tension in at least one of the firstpullwire and the second pullwire.

In Example 7, the subject matter of Example 6 is optionally configuredsuch that actuation of the first actuator causes rotation of the firstthreaded member.

In Example 8, the subject matter of Example 7 optionally includes afirst drive nut theadably coupled to the first threaded member. Thefirst and second pullwires are operably coupled to the first drive nut,wherein rotation of the first threaded member causes translation of thefirst drive nut along the longitudinal axis of the handle and, in turn,tension in at least one of the first pullwire and the second pullwire.

In Example 9, the subject matter of Example 8 is optionally configuredsuch that proximal translation of the first drive nut causes tension inthe first pullwire and distal translation of the first drive nut causestension in the second pullwire.

In Example 10, the subject matter of Example 9 optionally includes afirst U-shaped member configured to change a direction of the secondpullwire. The second pullwire extends proximally from the first drivenut to the first U-shaped member, around the first U-shaped member, anddistally from the first U-shaped member to proximate the distal tip ofthe elongate shaft.

In Example 11, the subject matter of any one of Examples 6-10 optionallyincludes a second threaded member disposed within the handle and movablewith actuation of the second actuator. The second threaded member isoperably coupled to the third and fourth pullwires, wherein movement ofthe second threaded member causes tension in at least one of the thirdpullwire and the fourth pullwire.

In Example 12, the subject matter of Example 11 is optionally configuredsuch that actuation of the second actuator causes rotation of the secondthreaded member.

In Example 13, the subject matter of Example 12 optionally includes asecond drive nut theadably coupled to the second threaded member. Thethird and fourth pullwires are operably coupled to second drive nut,wherein rotation of the second threaded member causes translation of thesecond drive nut along the longitudinal axis of the handle and, in turn,tension in at least one of the third pullwire and the fourth pullwire.

In Example 14, the subject matter of Example 13 is optionally configuredsuch that proximal translation of the second drive nut causes tension inthe third pullwire and distal translation of the second drive nut causestension in the fourth pullwire.

In Example 15, the subject matter of Example 14 optionally includes asecond U-shaped member configured to change a direction of the fourthpullwire. The fourth pullwire extends proximally from the second drivenut to the second U-shaped member, around the second U-shaped member,and distally from the second U-shaped member to proximate the distal tipof the elongate shaft.

In Example 16, the subject matter of any one of Examples 11-15 isoptionally configured such that the first threaded member at leastpartially overlaps the second threaded member. The second threadedmember is disposed at least partially within the first threaded member.

Example 17 can include, or can optionally be combined with any one ofExamples 1-16 to include subject matter that can include a steerablemedical device including a handle including a longitudinal axis. Anelongate shaft extends distally from the handle. The elongate shaftincludes a distal tip and a lumen through the elongate shaft. At leastfour pullwires are disposed within the handle and extend to and areanchored proximate the distal tip of the elongate shaft. The at leastfour pullwires include a first pullwire, a second pullwire, a thirdpullwire, and a fourth pullwire. At least two actuators are associatedwith the handle. The at least two actuators include a first actuator anda second actuator. At least two threaded members are disposed within thehandle. The at least two threaded members include a first threadedmember and a second threaded member. The first threaded member ismovable with actuation of the first actuator, and the second threadedmember is movable with actuation of the second actuator. At least twodrive nuts are disposed within the handle. The at least two drive nutsinclude a first drive nut and a second drive nut. The first drive nut istheadably coupled to the first threaded member and translatable alongthe longitudinal axis of the handle with movement of the first threadedmember. The second drive nut is theadably coupled to the second threadedmember and translatable along the longitudinal axis of the handle withmovement of the second threaded member. The first and second pullwiresare operably coupled to the first drive nut, and the third and fourthpullwires are operably coupled to the second drive nut. Actuation of thefirst actuator in a first actuator direction causes tension in the firstpullwire and deflection of the distal tip in a first tip direction.Actuation of the first actuator in a second actuator direction causestension in the second pullwire and deflection of the distal tip in asecond tip direction substantially opposite the first tip direction.Actuation of the second actuator in a first actuator direction causestension in the third pullwire and deflection of the distal tip in athird tip direction different from the first tip direction and thesecond tip direction. Actuation of the second actuator in a secondactuator direction causes tension in the fourth pullwire and deflectionof the distal tip in a fourth tip direction substantially opposite thethird tip direction.

In Example 18, the subject matter of Example 17 is optionally configuredsuch that proximal translation of the first drive nut causes tension inthe first pullwire and distal translation of the first drive nut causestension in the second pullwire. Proximal translation of the second drivenut causes tension in the third pullwire and distal translation of thesecond drive nut causes tension in the fourth pullwire.

In Example 19, the subject matter of any one of Examples 17-18 isoptionally configured such that the first threaded member at leastpartially overlaps the second threaded member. The second threadedmember is disposed at least partially within the first threaded member.

In Example 20, the subject matter of any one of Examples 17-19 isoptionally configured such that the first actuator and the secondactuator are each independently rotatable about the longitudinal axis ofthe handle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a steerable medical device inaccordance with at least one example of the invention.

FIG. 2 is a side view of the steerable medical device of FIG. 1.

FIG. 3 is a proximally-facing perspective view of a handle of thesteerable medical device of FIG. 1, the handle having part of a handlehousing removed.

FIG. 4 is a distally-facing perspective view of the handle of FIG. 3,the handle having part of the handle housing removed.

FIG. 5 is a side elevational view of the handle of FIG. 3, the handlehaving part of the handle housing removed.

FIG. 6 is a side elevational view of the handle of FIG. 3, the handlehaving part of the handle housing and some internal components of thehandle removed.

FIG. 7 is a perspective cross-sectional view of the handle of FIG. 3.

FIG. 8 is an exploded perspective view of a distal end the handle ofFIG. 3.

FIG. 9 is an exploded perspective view of a distal end the handle ofFIG. 3.

FIG. 10 is a perspective view of a pullwire connection ring of thesteerable medical device of FIG. 1.

FIG. 11 is a perspective view of movement of a tip of the steerablemedical device of FIG. 1 with actuation of a one control in onedirection.

FIG. 12 is a perspective view of movement of the tip of the steerablemedical device of FIG. 1 with actuation of a one control in bothdirections.

FIG. 13 is a perspective view of movement of the tip of the steerablemedical device of FIG. 1 with actuation of both controls in bothdirections.

DETAILED DESCRIPTION

The present patent application relates to a device, an apparatus, asystem, and a method for providing multidirectional steering capability.In various examples, as described herein, the device, apparatus, system,and method can include multiple degrees of motion to allow for increasedmaneuverability within a patient. The present inventors have recognizedthat, in some examples, the present subject matter can be used toprovide a device with multiple degrees of motion to allow for a tip ofthe device having a 360-degree range of deflection. In some examples,the device can include a medical device, such as, but not limited to acatheter, a sheath, an introducer, a guidewire, or the like.

In various medical procedures, it can be desirable to have a medicaldevice that includes a tip that can articulate in multiple directions,such as, for instance, a 360-degree range of deflection. Medicalprocedures for which such a device would be helpful include, but are notlimited to, an intravascular ultrasound (IVUS) procedure. In someexamples, a catheter handle mechanism configured to articulate fourindividual pullwires can be used to achieve this range of motion.Additionally, in some examples, such a medical device can be used withone hand to steer the distal end of the medical device. In variousexamples, such a handle mechanism can be used in anysteerable/deflectable catheter, therapy device, or other medical device.

The following co-owned applications relate to steerable medical devicesand are hereby incorporated by reference in their entireties: U.S.application Ser. No. 12/463,570, now U.S. Pat. No. 8,308,659, filed May11, 2009 and entitled “BI-DIRECTIONAL SHEATH DEFLECTION MECHANISM”; andU.S. application Ser. No. 13/269,858, now U.S. Pat. No. 9,149,607, filedOct. 10, 2011 and entitled “BI-DIRECTIONAL CATHETER STEERING HANDLE.”

Referring now to FIGS. 1 and 2, in some examples, a steerable medicaldevice 100 is configured to provide multiple degrees of motion tofacilitate navigation and/or articulation of the steerable medicaldevice 100 within a patient. For instance, in some examples, thesteerable medical device 100 includes a 360-degree range of deflection.In some examples, the steerable medical device 100 includes a handle 104including a longitudinal axis 105. In some examples, the handle 104includes two handle portions 104A, 104B that are coupled together toenclose at least a portion of a handle mechanism 140 (described ingreater detail below) within the handle 104. Although shown anddescribed herein as halving two portions 104A, 104B, in other examples,the handle 104 can include fewer or more than two portions, provided thehandle mechanism 140 is able to be placed within the handle 104. In someexamples, the handle portions 104A, 104B can be coupled together invarious ways, including, but not limited to, the handle portions 104A,104B being configured to be snap fit or otherwise frictionally engagedtogether; the handle portions 104A, 104B being welded (ultrasonic,vibration, laser, or the like) together; the handle portions 104A, 104Bbeing adhered together using an adhesive (epoxy, silicone, polyurethane,or the like); or a combination thereof. In some examples, the handleportions 104A, 104B are shaped and sized to allow for at least a portionof the handle mechanism 140 to be housed within an interior 104C of thehandle 104 with the handle portions 104A, 104B coupled together.

In some examples, the steerable medical device 100 includes an elongateshaft 108 extending distally from the handle 104. The elongate shaft, insome examples, includes a distal tip 108A and a lumen 108B (see FIG. 7)through the elongate shaft 108. In some examples, the elongate shaft 108extends from a distal end of the handle 104. In some examples, at leasta portion of the elongate shaft 108 is disposed within the handle 104.In further examples, the elongate shaft 108 extends from a valve member112 disposed at a proximal end of the handle 104, through the handle104, and out of the distal end of the handle 104. The elongate shaft108, in some examples, can include an over-molded hub on a proximal endof the elongate shaft 108 with keying ribs that secure the hub and, inturn, the elongate shaft 108 within the handle 104.

The valve member 112, in some examples, includes a valve housing 112Aengageable with the handle 104, for instance, within the proximal end ofthe housing 104. The valve member 112, in some examples, includes avalve cap 112B disposed at a proximal end of the valve housing 112A andcapturing a valve 112C between the valve cap 112B and the valve housing112A. The valve 112C, in some examples, is configured to limit expellingof fluid (for instance, a bodily fluid, a fluid introduced for theprocedure, or a combination of the two) to allow insertion of anintroducible device (such as, for instance, a guidewire, a catheter, adelivery device, a sensing device, an ablation device, or anothermedical device) into the steerable medical device 100. In some examples,it is contemplated that the valve member 112 need not include a valve112C, for instance, when fluid being expelled from the device 100 is notan issue. In this way, in some examples, the valve member 112 allowsinsertion of the introducible device into the steerable medical device100 and through the elongate shaft 108 to a location within a patient.In some examples, the valve member 112 can include a sideport 112D inthe valve housing 112A. The sideport 112D, in some examples, allows fora tube 113 and/or stopcock 114 to fluidly couple to the valve member 112to allow for introduction of a fluid (such as, but not limited to,saline, water, air, and/or nitrogen) or connection to a suction device,for stance, to remove a bodily fluid from within the patient and/or thesteerable medical device 100. In other examples, the valve member 112need not include a sideport if introduction and/or removal of one ormore fluids is not necessary for the steerable medical device 100.

In some examples, the elongate shaft 108 extends through a nose member116 disposed at the distal end of the handle 104. The nose member 116,in some examples, provides strain relief for the elongate shaft 108. Insome examples, the nose member 116 is substantially conically shaped,although this is not intended to be limiting. As such, in variousexamples, other shapes of the nose member 116 are contemplated herein.

In some examples, a support tube 120 is disposed within the handle 104.In some examples, the support tube 120 includes a lumen 121 through thesupport tube 120 sized and shaped to accept a portion of the elongateshaft 108 therein. The support tube 120, in some examples, is formedfrom a rigid material such as, but not limited to, plastic, metal, orthe like. In some examples, the support tube 120 includes one or morewindows 120C formed in the support tube 120. In some examples, thesupport tube 120 includes four windows 120C. In further examples, thesupport tube 120 includes four windows 120C formed in the support tube120 and equidistantly spaced from one another around a circumference ofthe support tube 120.

In some examples, the support tube 120 includes a proximal notch 120Aformed in a proximal end of the support tube 120 and a distal notch 120Bformed in a distal end of the support tube 120. In some examples, theproximal notch 120A is configured to accept a key 122A of a proximalinsert 122 when the proximal end of the support tube 120 is placedwithin an opening 122B of the proximal insert 122. In this way,interaction between the proximal notch 120A of the support tube 120 andthe key 122A of the proximal insert 122 inhibits rotation of the supporttube 120 relative to the proximal insert 122. The proximal insert 122,in some examples, is configured to engage with the handle 104 to inhibitrotation of the proximal insert 122 relative to the handle 104. In someexamples, the distal notch 120B is configured to accept a key 124A of adistal support 124 when the distal end of the support tube 120 is placedwithin an opening 124B of the distal support 122. In this way,interaction between the distal notch 120B of the support tube 120 andthe key 124A of the distal support 124 inhibits rotation of the supporttube 120 relative the distal support 124. In this way, in some examples,each of the handle 104, the support tube 120, the proximal insert 122,and the distal support 124 are engaged with one another and inhibitedfrom rotating with respect to one another. In some examples, the nosemember 116 is configured to engage with the distal support 124. In someexamples, the nose member 116 is configured to snap onto the distalsupport 124.

In some examples, the support tube 120 provides central support to thehandle 104 and the handle mechanism 140. In some examples, the supporttube 120 allows components of the handle mechanism 140 to rotate aboutan outer diameter of the support tube 120 while inhibiting the nosemember 116 from rotating.

In some examples, at least two actuators 128, 132 are associated withthe handle 104. In some examples, the at least two actuators 128, 132include a first actuator 128 and a second actuator 132. In otherexamples, the at least two actuators 128, 132 include more than twoactuators to allow for increased control of the device 100 or aspects ofthe device 100 if desirable for the particular application of the device100. In some examples, at least one of the two actuators 128, 132 isrotatable about the longitudinal axis 105 of the handle 104. That is, insome examples, the first and second actuators 128, 132 include knobsthat are rotatable with respect to the handle 104 about the longitudinalaxis 105 to control the device 100 (for instance, to control deflectionof the distal tip 108A of the elongate shaft 108 of the device 100).While the first and second actuators 128, 132 are shown as knobs herein,in other examples, it is contemplated that the first and secondactuators 128, 132 include a slider, a toggle switch, a knob rotatableabout an axis other than the longitudinal axis 105, or a combination oftwo different types of actuators, provided the first and secondactuators 128, 132 are capable of controlling the device 100 to performthe particular function of the device 100. In some examples, the firstactuator 128 and the second actuator 132 are each independentlyrotatable about the longitudinal axis 105 of the handle 104. That is,rotation of one of the first and second actuators 128, 132 does notcause rotation of the other of the first and second actuators 128, 132,thereby allowing independent control of each of the first and secondactuators 128, 132 by the physician or other user.

Referring to FIGS. 1-7, at least four pullwires 167, 169, 187, 189, insome examples, are disposed within the handle 104 and extend to and areanchored proximate the distal tip 108A of the elongate shaft 108. Insome examples, the at least four pullwires 167, 169, 187, 189 include afirst pullwire 167, a second pullwire 169, a third pullwire 187, and afourth pullwire 189. In some examples, the at least four pullwires 167,169, 187, 189 extend within the elongate shaft 108 to proximate thedistal tip 108A of the elongate shaft 108. In some examples, the atleast four pullwires 167, 169, 187, 189 are operably coupled to thefirst and second actuators 128, 132, such that actuation of the firstactuator 128 and/or the second actuator 132 causes tension in at leastone of the at least four pullwires 167, 169, 187, 189, thereby causingthe distal tip 108A of the elongate shaft 108 to deflect, as will bedescribed in more detail below. In some examples, the handle mechanism140 is configured to cause deflection of the distal tip 108A of theelongate shaft 108 with actuation of the first actuator 128 and/or thesecond actuator 132.

In some examples, the first, second, third, and fourth pullwires 167,169, 187, 189 extend out from the elongate shaft 108 within the handle104 in order to operably couple with the first and second actuators 128,132. Because, in some examples, the support tube 120 is disposed overthe elongate shaft 108, the support tube 120 can include one or morewindows 120C formed in a sidewall of the support tube 120 at one or morelocations around the support tube 120 to allow for the first, second,third, and fourth pullwires 167, 169, 187, 189 to extend out from theelongate shaft 108 and the support tube 120 to the handle mechanism 140in order to operably couple the first, second, third, and fourthpullwires 167, 169, 187, 189 to the first and second actuators 128, 132.In some examples, the support tube 120 includes four windows 120Cdisposed around the support tube 120, such that each of the first,second, third, and fourth pullwires 167, 169, 187, 189 exits through itsown window 120C in the support tube 120. In other examples, the supporttube 120 can include fewer than four windows 120C, such that one or moreof the first, second, third, and fourth pullwires 167, 169, 187, 189share at least one of the windows 120C.

In some examples, the handle mechanism 140 includes a first threadedmember 154 disposed within the handle 104 and movable with actuation ofthe first actuator 128. In some examples, the first threaded member 154includes at least one thread 154A disposed in an outer surface of thefirst threaded member 154. The first threaded member 154, in someexamples, is operably coupled to the first and second pullwires 167,169, such that movement of the first threaded member 154 causes tensionin at least one of the first pullwire 167 and the second pullwire 169.In some examples, rotation of the first actuator 128 causes rotation ofthe first threaded member 154. In some examples, the first actuator 128is coupled directly to the first threaded member 154. In some examples,the first actuator 128 is coupled to a first drive ring 150, and thefirst drive ring 150 is coupled to the first threaded member 154. Thefirst actuator 128, in some examples, includes a notch 128A that iscomplementarily sized and shaped to accept a key 150A of the first drivering 150, such that, with the first drive ring 150 disposed within anopening of the first actuator 128, the key 150A interacts with the notch128A to inhibit relative rotation between the first actuator 128 and thefirst drive ring 150. In some examples, the first drive ring 150 can besimilarly coupled with a keyed configuration to the first threadedmember 154 to inhibit relative rotation between the first drive ring 150and the first threaded member 154. In this way, in some examples,rotation of the first actuator 128 can cause rotation of the firstthreaded member 154.

In some examples, the handle mechanism 140 includes a first drive nut158 theadably coupled to the first threaded member 154. In someexamples, the first drive nut 158 includes a substantially semi-tubularshape configured to partially wrap around the first threaded member 154with at least one thread 158B disposed on an inside surface of the firstdrive nut 158 and sized and shaped to threadably engage with the atleast one thread 154A of the first threaded member 154. In someexamples, the first drive nut 158 is constrained from rotating whenthreadably coupled to the first threaded member 154 and disposed inplace within the interior 104C of the handle 104. In further examples,the handle 104 includes a ridge 104D or other interior surface featureconfigured to abut or otherwise interact with the first drive nut 158 toinhibit the first drive nut 158 from rotating within the handle 104. Inthis way, in some examples, rotation of the first threaded member 154(for instance, via rotation or other actuation of the first actuator128) causes translation of the first drive nut 158 along thelongitudinal axis 105 of the handle 104 as the at least one thread 154Arotates and, through interaction with the at least one thread 158B ofthe first drive nut 158, imparts translational motion to the first drivenut 158 within the handle 104.

In some examples, the first and second pullwires 167, 169 are operablycoupled to first drive nut 158, such that, with rotation of the firstthreaded member 154, the first drive nut 158 translates along thelongitudinal axis 105 of the handle 104 and, in turn, causes tension inat least one of the first pullwire 167 and the second pullwire 169. Forinstance, in some examples, the first and second pullwires 167, 169 arecoupled to first and second pullwire blocks 166, 168, respectively. Insome examples, ends of the first and second pullwires 167, 169 arerespectively coupled to the first and second pullwire blocks 166, 168.In some examples, the first and second pullwire blocks 166, 168 aredisposed within the interior 104C of the handle 104 and on oppositesides of an abutment 158A of the first drive nut 158. In some examples,the first pullwire block 166 is disposed on a proximal side of theabutment 158A with the first pullwire 167 extending distally from thefirst pullwire block 166, and the second pullwire block 168 is disposedon a distal side of the abutment 158A with the second pullwire 169extending proximally from the second pullwire block 168. In this way, insome examples, proximal translation of the first drive nut 158 along thelongitudinal axis 105 of the handle 104 causes the abutment 158A of thefirst drive nut 158 to abut and push the first pullwire block 166 in aproximal direction, thereby causing tension in the first pullwire 167.Additionally, in some examples, distal translation of the first drivenut 158 along the longitudinal axis 105 of the handle 104 causes theabutment 158A of the first drive nut 158 to abut and push the secondpullwire block 168 in a distal direction, thereby causing tension in thesecond pullwire 169. The first pullwire 167, in some examples, runsdirectly from the elongate shaft 108 through a first through hole in theabutment 158A of the first drive nut 158 from the distal side of theabutment 158A. The first pullwire block 166 can then be threaded overand tightened down onto the first pullwire 167 on the proximal side ofthe abutment 158A of the first drive nut 158, allowing the firstpullwire 167 to be tensioned when the first drive nut 158 is translatedproximally along the longitudinal axis 105 of the handle 104 whileremaining without load when the first drive nut 158 is translateddistally along the longitudinal axis 105 of the handle 104.

Because the second pullwire 169 ultimately extends distally down theelongate shaft 108 to proximate the distal tip 108A of the elongateshaft 108, in some examples, the second pullwire 169, which initiallyextends proximally from the second pullwire block 168, needs to changedirection. To that end, in some examples, a change of direction membercan be used to route the second pullwire 169 from a proximally extendingdirection to a distally extending direction. In various examples, thechange of direction member can take various forms, including, but notlimited to, a pulley; a substantially U-shaped channel, member, or othersuch structure; a pin, a rod, or another similar structure; asubstantially U-shaped tube; or the like. In some examples, a firstU-shaped member 162 is configured to change a direction of the secondpullwire 169, such that the second pullwire 169 initially extendsproximally from the second pullwire block 168 and/or the first drive nut158 to the first U-shaped member 162. From there, the second pullwire169 extends around the first U-shaped member 162 and then distally fromthe first U-shaped member 162 to proximate the distal tip 108A of theelongate shaft 108. In this way, by translating the first drive nut 158proximally within the handle 104 along the longitudinal axis 105, thefirst pullwire 167 can be put under tension, and, by translating thefirst drive nut 158 distally within the handle 104 along thelongitudinal axis 105, the second pullwire 169 can be put under tension.In some examples, the first U-shaped member 162 is formed from a tube,such as, but not limited to, a hypotube, that is formed intosubstantially a U-shape. The second pullwire 169, in some examples,extends proximally from the second pullwire block 168, through a lumenof the first U-shaped member 162, and then distally from the firstU-shaped member 162 through the elongate shaft 108 to proximate thedistal tip 108A of the elongate shaft 108. In some examples, once thesecond pullwire 169 exits the elongate shaft 108, the second pullwire169 is routed through the first U-shaped member 162 (for instance, acurved hypotube). In some examples, a composite tubing jacket can beused to shield the second pullwire 169 within the first U-shaped member162. In some examples, the composite tubing jacket can include alubricious inner surface to reduce friction on the second pullwire 169.In some examples, the second pullwire 169 can include a braidreinforcement to maintain durability and wear resistance. The secondpullwire 169, in some examples, then runs through a second through holeon the proximal face of the abutment 158A of the first drive nut 158. Onthe distal side of the second through hole, in some examples, the secondpullwire block 168 can be threaded over the second pullwire 169 andtightened onto the second pullwire 169, thereby locking the secondpullwire 169 in place. Such a configuration, in some examples, allowsthe second pullwire 169 to be tensioned when the first drive nut 158 istranslated distally along the longitudinal axis 105 of the handle 104while remaining without load when the first drive nut 158 is translatedproximally along the longitudinal axis 105 of the handle 104.

In some examples, the handle mechanism 140 includes a second threadedmember 174 disposed within the handle 104 and movable with actuation ofthe second actuator 132. In some examples, the second threaded member174 includes at least one thread 174A disposed in an outer surface ofthe second threaded member 174. The second threaded member 174, in someexamples, is operably coupled to the third and fourth pullwires 187,189, such that movement of the second threaded member 174 causes tensionin at least one of the third pullwire 187 and the fourth pullwire 189.In some examples, rotation of the second actuator 132 causes rotation ofthe second threaded member 174. In some examples, the second actuator132 is coupled directly to the second threaded member 174. In someexamples, the second actuator 132 is coupled to a second drive ring 170,and the second drive ring 170 is coupled to the second threaded member174. The second actuator 132, in some examples, includes a notch 132Athat is complementarily sized and shaped to accept a key 170A of thesecond drive ring 170, such that, with the second drive ring 170disposed within an opening of the second actuator 132, the key 170Ainteracts with the notch 132A to inhibit relative rotation between thesecond actuator 132 and the second drive ring 170. In some examples, thesecond drive ring 170 can be similarly coupled with a keyedconfiguration to the second threaded member 174 to inhibit relativerotation between the second drive ring 170 and the second threadedmember 174. In this way, in some examples, rotation of the secondactuator 132 can cause rotation of the second threaded member 174. Insome examples, the second drive wheel 170 is attached to a distal lock126, which, in turn, is coupled to the distal support 124. In this way,in some examples, the distal lock 126 allows rotation of the secondactuator 132, the distal lock 126 and the second drive ring 170 aroundthe distal support 124 but inhibits distal or proximal movement of thesecond actuator 132, the distal lock 126 and the second drive ring 170relative the handle 104 and the first actuator 128. In some examples,the distal lock 126 includes a first distal lock portion 126A and asecond distal lock portion 126B that are engageable together to form thedistal lock 126, for instance, to facilitate assembly of the handlemechanism 140.

In some examples, the handle mechanism 140 includes a second drive nut178 theadably coupled to the second threaded member 174. In someexamples, the second drive nut 178 includes a substantially semi-tubularshape configured to partially wrap around the second threaded member 174with at least one thread 178B disposed on an inside surface of thesecond drive nut 178 and sized and shaped to threadably engage with theat least one thread 174A of the second threaded member 174. In someexamples, the second drive nut 178 is constrained from rotating whenthreadably coupled to the second threaded member 174 and disposed inplace within the interior 104C of the handle 104. In further examples,one or more catches 179 or other structures are included within thehandle 104 and configured to abut or otherwise interact with the seconddrive nut 178 to inhibit the second drive nut 178 from rotating withinthe handle 104. In some examples, the second drive nut 178 abuts twocatches 179 to constrain the second drive nut 178 from rotating withinthe handle 104. In this way, in some examples, rotation of the secondthreaded member 174 (for instance, via rotation or other actuation ofthe second actuator 132) causes translation of the second drive nut 178along the longitudinal axis 105 of the handle 104 as the at least onethread 174A rotates and, through interaction with the at least onethread 178B of the second drive nut 178, imparts translational motion tothe first drive nut 178 within the handle 104.

In some examples, the third and fourth pullwires 187, 189 are operablycoupled to second drive nut 178, such that, with rotation of the secondthreaded member 174, the second drive nut 178 translates along thelongitudinal axis 105 of the handle 104 and, in turn, causes tension inat least one of the third pullwire 187 and the fourth pullwire 189. Forinstance, in some examples, the third and fourth pullwires 187, 189 arecoupled to third and fourth pullwire blocks 186, 188, respectively. Insome examples, ends of the third and fourth pullwires 187, 189 arerespectively coupled to the third and fourth pullwire blocks 186, 188.In some examples, the third and fourth pullwire blocks 186, 188 aredisposed within the interior 104C of the handle 104 and on oppositesides of an abutment 178A of the second drive nut 178. In some examples,the third pullwire block 186 is disposed on a proximal side of theabutment 178A with the third pullwire 187 extending distally from thethird pullwire block 186, and the fourth pullwire block 188 is disposedon a distal side of the abutment 178A with the fourth pullwire 189extending proximally from the fourth pullwire block 188. In this way, insome examples, proximal translation of the second drive nut 178 alongthe longitudinal axis 105 of the handle 104 causes the abutment 178A ofthe second drive nut 178 to abut and push the third pullwire block 186in a proximal direction, thereby causing tension in the third pullwire187. Additionally, in some examples, distal translation of the seconddrive nut 178 along the longitudinal axis 105 of the handle 104 causesthe abutment 178A of the second drive nut 178 to abut and push thefourth pullwire block 188 in a distal direction, thereby causing tensionin the fourth pullwire 189. The third pullwire 187, in some examples,runs directly from the elongate shaft 108 through a first through holein the abutment 178A of the second drive nut 178 from the distal side ofthe abutment 178A. The third pullwire block 186 can then be threadedover and tightened down onto the third pullwire 187 on the proximal sideof the abutment 178A of the second drive nut 178, allowing the thirdpullwire 187 to be tensioned when the second drive nut 178 is translatedproximally along the longitudinal axis 105 of the handle 104 whileremaining without load when the second drive nut 178 is translateddistally along the longitudinal axis 105 of the handle 104.

Because the fourth pullwire 189 ultimately extends distally down theelongate shaft 108 to proximate the distal tip 108A of the elongateshaft 108, in some examples, the fourth pullwire 189, which initiallyextends proximally from the fourth pullwire block 188, needs to changedirection. To that end, in some examples, a change of direction membercan be used to route the fourth pullwire 189 from a proximally extendingdirection to a distally extending direction. In various examples, thechange of direction member can take various forms, including, but notlimited to, a pulley; a substantially U-shaped channel, member, or othersuch structure; a pin, a rod, or another similar structure; asubstantially U-shaped tube; or the like. In some examples, a secondU-shaped member 182 is configured to change a direction of the fourthpullwire 189, such that the fourth pullwire 189 initially extendsproximally from the fourth pullwire block 188 and/or the second drivenut 178 to the second U-shaped member 182. From there, the fourthpullwire 189 extends around the second U-shaped member 182 and thendistally from the second U-shaped member 182 to proximate the distal tip108A of the elongate shaft 108. In this way, by translating the seconddrive nut 178 proximally within the handle 104 along the longitudinalaxis 105, the third pullwire 187 can be put under tension, and, bytranslating the second drive nut 178 distally within the handle 104along the longitudinal axis 105, the fourth pullwire 189 can be putunder tension. In some examples, the second U-shaped member 182 isformed from a tube, such as, but not limited to, a hypotube, that isformed into substantially a U-shape. The fourth pullwire 189, in someexamples, extends proximally from the fourth pullwire block 188, througha lumen of the second U-shaped member 182, and then distally from thesecond U-shaped member 182 through the elongate shaft 108 to proximatethe distal tip 108A of the elongate shaft 108.

In some examples, once the fourth pullwire 189 exits the elongate shaft108, the fourth pullwire 189 is routed through the second U-shapedmember 182 (for instance, a curved hypotube). In some examples, acomposite tubing jacket can be used to shield the fourth pullwire 189within the second U-shaped member 182. In some examples, the compositetubing jacket can include a lubricious inner surface to reduce frictionon the fourth pullwire 189. In some examples, the fourth pullwire 189can include a braid reinforcement to maintain durability and wearresistance. The fourth pullwire 189, in some examples, then runs througha second through hole on the proximal face of the abutment 178A of thesecond drive nut 178. On the distal side of the second through hole, insome examples, the fourth pullwire block 188 can be threaded over thefourth pullwire 189 and tightened onto the fourth pullwire 189, therebylocking the fourth pullwire 189 in place. Such a configuration, in someexamples, allows the fourth pullwire 189 to be tensioned when the seconddrive nut 178 is translated distally along the longitudinal axis 105 ofthe handle 104 while remaining without load when the second drive nut178 is translated proximally along the longitudinal axis 105 of thehandle 104.

In some examples, the first threaded member 154 at least partiallyoverlaps the second threaded member 174, such that the second threadedmember 174 is disposed at least partially within the first threadedmember 154. In this way, in some examples, use of space within theinterior 104 can be substantially optimized in order to keep an overallsize of the handle 104 relatively small and manageable by the physicianor other user. In some examples, the second threaded member 174 rotatesaround the support tube 120 with actuation of the second actuator 132.The first threaded member 154, in some examples, rotates around thesecond threaded member 174 and/or the second drive nut 178 withactuation of the first actuator 128. In this way, in some examples,multidirectional control of the distal tip 108A can be achieved, and therelatively numerous components of the handle mechanism 140 to achievesuch multidirectional control can be fit within the confines of theinterior 104C of the handle 104, while keeping the size of the handle104 relatively manageable by the physician or other user, withoutinterference between various components of the handle mechanism 140.

Referring to FIG. 10, the pullwire ring 109, in some examples, can bedisposed proximate the distal tip 108A of the elongate shaft 108. Invarious examples, the pullwire ring 109 can be adhered to, molded into,welded to, or otherwise attached to the elongate shaft 108 proximate thedistal tip 108A of the elongate shaft 108. In some examples, the first,second, third, and fourth pullwires 167, 169, 187, 189 are attached tothe pullwire ring 109. In various examples, the first, second, third,and fourth pullwires 167, 169, 187, 189 can be attached to the pullwirering 109 by welding, soldering, brazing adhesive, mechanical fastener,or a combination thereof. In some examples, the first, second, third,and fourth pullwires 167, 169, 187, 189 are equidistantly spaced aroundthe pullwire ring 109 from one another. In some examples, the first andsecond pullwires 167, 169 are spaced around the pullwire ring 109substantially 180 degrees from one another. In some examples, the thirdand fourth pullwires 187, 189 are spaced around the pullwire ring 109substantially 180 degrees from one another.

Referring now to FIGS. 11-13, various examples of deflection of thedistal tip 108A of the elongate shaft 108 are shown. Through actuationof one or both of the first and second actuators 128, 132, variouspositions of the distal tip 108A of the elongate shaft 108 can beachieved. For instance, in some examples, actuation of the firstactuator 128 in a first actuator direction causes tension in the firstpullwire 167 and deflection of the distal tip 108A in a first tipdirection A. In further examples, actuation of the first actuator 128 ina second actuator direction causes tension in the second pullwire 169and deflection of the distal tip 108A in a second tip direction Bsubstantially opposite the first tip direction A. In some examples,rotation of the first actuator 128 in a first rotational direction (forinstance, counterclockwise) causes tension in the first pullwire 167 todeflect the distal tip 108A in the first tip direction A, and rotationof the first actuator 128 in a second rotational direction (forinstance, clockwise) causes tension in the second pullwire 169 todeflect the distal tip 108A in the second tip direction B. In furtherexamples, actuation of the second actuator 132 in a first actuatordirection causes tension in the third pullwire 187 and deflection of thedistal tip 108A in a third tip direction C different from the first tipdirection A and the second tip direction B. In still further examples,actuation of the second actuator 132 in a second actuator directioncauses tension in the fourth pullwire 189 and deflection of the distaltip 108A in a fourth tip direction D substantially opposite the thirdtip direction C. In some examples, rotation of the second actuator 132in a first rotational direction (for instance, counterclockwise) causestension in the third pullwire 187 to deflect the distal tip 108A in thethird tip direction C, and rotation of the second actuator 132 in asecond rotational direction (for instance, clockwise) causes tension inthe fourth pullwire 189 to deflect the distal tip 108A in the fourth tipdirection D. Referring specifically to FIG. 13, in some examples, byactuating each of the first and second actuators 128, 132, the elongateshaft 108 can be deflected in various ways and a plurality of positionsof the distal tip 108A can be achieved. As demonstrated in FIG. 13,substantially any position of the distal tip 108A can be achieved withina spherical area at the distal end of the elongate shaft 108A. In thisway, such maneuverability can facilitate navigation of the distal tip108A and/or the elongate shaft 108 within the patient and, once in placewithin the patient, articulation of the distal tip 108A in substantiallyany direction to facilitate any of various procedures intended to beperformed by the device 100 or with assistance from the device 100.

Referring back to FIG. 2, the placement of the first and secondactuators 128, 132, in some examples, allows for one-handed operation bythe physician or other user. That is, having both the first actuator 128and the second actuator 132 at the distal end of the handle 104, thephysician or other user can hold onto the handle 104 with one hand anduse a thumb and/or a finger (for instance, the index finger) to controleach of the first and second actuators 128, 132. One-handed control ofthe device 100 is advantageous in that it frees up the other hand of thephysician or other user to do other things and/or control other devicesduring the procedure for which the device 100 is being used. Moreover,each of the first and second actuators 128, 132 can be actuatedindependently without interfering with the actuation of the other of thefirst and second actuators 128, 132. This is achieved, in some examples,by constraining each of the first and second actuators 128, 132 fromtranslating during rotation of the first and second actuators 128, 132,as described herein. Additionally, actuation of the various componentsof the handle mechanism 140 associated with the first actuator 128 canbe accomplished without impacting actuation of the various components ofthe handle mechanism 140 associated with the second actuator 132 andvice versa. For instance, translating the first drive nut 158 does notaffect translating the second drive nut 178 and vice versa. In this way,independent control of the first and second actuators 128, 132 can beachieved.

In some examples, the four pullwires 167, 169, 187, 189 can be tensionedat different rates using the first and second actuators 128, 132 toprovide distal tip 108A deflection in substantially 360 degrees.Additionally, in some examples, the handle mechanism 140 enablessubstantially 360-degree steering of the elongate shaft 108 of thedevice by using only two sliding components (the first and second drivenuts 158, 178) within the handle 104. Having only two sliding memberscan allow for more/easier control over the location of the pullwireblocks 166, 168, 186, 188 which can impact the amount of “dead zone”when at least one of the first and second actuators is rotated (theamount of rotation in which neither pullwire associated with thatactuator is engaged). Minimizing such “dead zone” can be advantageous.

In some examples, by using two U-shaped members 162, 182 (for instance,two curved hypotube segments), two pullwires 169, 189 of the fourpullwires 167, 169, 187, 189 are redirected substantially 180 degrees,which reverses the direction of the pull required to activate these twowires 169, 189. This allows each of the two independent slidingcomponents (the first and second drive nuts 158, 178) to each be used ona pair of pullwires (pullwires 167, 169 for the first drive nut 158 andpullwires 187, 189 for the second drive nut 178). Each sliding component158, 178 is independently mated to the respective actuator 128, 132. Inthis way, the distal tip 108A can achieve a full range ofdeflection/steering through a coordinated rotation of each of the firstand second actuators 128, 132.

The present inventors have recognized various advantages of the subjectmatter described herein. For instance, in some examples, the examples ofdevices, apparatuses, systems, and methods described herein can be usedto provide multidirectional steering capability. In some examples, thesubject matter described herein can provide multiple degrees of motionto a medical device to allow for increased maneuverability within apatient. In various examples, the device, apparatus, system, and methodcan be used to provide a device with multiple degrees of motion to allowfor a tip of the device to have a 360-degree range of deflection. Such adevice is further advantageous, in some examples, since such a range ofdeflection can be achieved using one hand to steer the distal end of themedical device, thereby freeing the other hand for other things, such ascontrolling another device used in the procedure. While variousadvantages of the example apparatuses are listed herein, this list isnot considered to be complete, as further advantages may become apparentfrom the description and figures presented herein.

Although the subject matter of the present patent application has beendescribed with reference to various examples, workers skilled in the artwill recognize that changes can be made in form and detail withoutdeparting from the scope of the subject matter recited in the belowclaims.

The above Detailed Description includes references to the accompanyingdrawings, which form a part of the Detailed Description. The drawingsshow, by way of illustration, specific examples in which the presentapparatuses and methods can be practiced. These embodiments are alsoreferred to herein as “examples.”

The above Detailed Description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreelements thereof) can be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. Also, various features or elementscan be grouped together to streamline the disclosure. This should not beinterpreted as intending that an unclaimed disclosed feature isessential to any claim. Rather, inventive subject matter can lie in lessthan all features of a particular disclosed embodiment. Thus, thefollowing claims are hereby incorporated into the Detailed Description,with each claim standing on its own as a separate embodiment. The scopeof the invention should be determined with reference to the appendedclaims, along with the full scope of equivalents to which such claimsare entitled.

In this document, the terms “a” or “an” are used to include one or morethan one, independent of any other instances or usages of “at least one”or “one or more.” In this document, the term “or” is used to refer to anonexclusive or, such that “A or B” includes “A but not B,” “B but notA,” and “A and B,” unless otherwise indicated. In this document, theterms “about” and “approximately” or similar are used to refer to anamount that is nearly, almost, or in the vicinity of being equal to astated amount.

In the appended claims, the terms “including” and “in which” are used asthe plain-English equivalents of the respective terms “comprising” and“wherein.” Also, in the following claims, the terms “including” and“comprising” are open-ended, that is, an apparatus or method thatincludes elements in addition to those listed after such a term in aclaim are still deemed to fall within the scope of that claim. Moreover,in the following claims, the terms “first,” “second,” and “third,” etc.are used merely as labels, and are not intended to impose numericalrequirements on their objects.

The Abstract is provided to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims.

1. (canceled)
 2. A steerable medical device comprising: a handleincluding a longitudinal axis; an elongate shaft extending distally fromthe handle, the elongate shaft including a distal tip and a lumenthrough the elongate shaft; at least four pullwires disposed within thehandle and extending to and anchored proximate the distal tip of theelongate shaft, the at least four pullwires including a first pullwire,a second pullwire, a third pullwire, and a fourth pullwire; and at leasttwo actuators associated with the handle, the at least two actuatorsincluding a first actuator and a second actuator, the at least twoactuators being operably coupled to the at least four pullwires, suchthat actuation of the first actuator causes tension in either the firstpullwire or the second pullwire and deflection of the distal tip in afirst tip direction or a second tip direction, respectively, andactuation of the second actuator causes tension in either the thirdpullwire or the fourth pullwire and deflection of the distal tip in athird tip direction or a fourth tip direction, respectively, whereineach of the first and second actuators is independently actuatablewithout interfering with the actuation of the other of the first andsecond actuators.
 3. The steerable medical device of claim 2, whereinactuation of the first and second actuators includes rotation of thefirst and second actuators, each of the first and second actuators beingconstrained from translating during rotation of the first and secondactuators.
 4. The steerable medical device of claim 2, comprising asupport tube disposed within the handle and rotationally andtranslationally constrained with respect to the handle, wherein thefirst and second actuators are operably coupled to the support tube,such that the first and second actuators are each independentlyrotatable about the support tube and each constrained from longitudinalmovement with respect to the support tube.
 5. The steerable medicaldevice of claim 4, wherein the second actuator is operably coupled toand translationally constrained by the support tube.
 6. The steerablemedical device of claim 2, comprising: a first threaded member disposedwithin the handle and movable with the actuation of the first actuatorin either the first actuator direction or the second actuator direction,the first threaded member being operably coupled to the first and secondpullwires, wherein movement of the first threaded member causes thetension in at least one of the first pullwire and the second pullwire;and a second threaded member disposed within the handle and movable withthe actuation of the second actuator in either the first actuatordirection or the second actuator direction, the second threaded memberbeing operably coupled to the third and fourth pullwires, whereinmovement of the second threaded member causes the tension in at leastone of the third pullwire and the fourth pullwire, wherein the firstthreaded member at least partially overlaps the second threaded member,the second threaded member being disposed at least partially within thefirst threaded member, the first and second threaded members beingindependently actuatable with respect to one another.
 7. The steerablemedical device of claim 6, wherein the first threaded member istranslationally constrained but rotatable within the handle, the firstactuator being operably coupled to and translationally constrained bythe first threaded member.
 8. The steerable medical device of claim 6,comprising a first drive nut theadably coupled to the first threadedmember, the first drive nut being rotationally constrained by thehandle, the first and second pullwires being operably coupled to thefirst drive nut, wherein the rotation of the first threaded membercauses translation of the first drive nut along the longitudinal axis ofthe handle and, in turn, the tension in at least one of the firstpullwire and the second pullwire.
 9. The steerable medical device ofclaim 8, comprising a second drive nut theadably coupled to the secondthreaded member, the second drive nut being rotationally constrained bythe handle, the third and fourth pullwires being operably coupled to thesecond drive nut, wherein the rotation of the second threaded membercauses the translation of the second drive nut along the longitudinalaxis of the handle and, in turn, the tension in at least one of thethird pullwire and the fourth pullwire.
 10. The steerable medical deviceof claim 9, comprising first and second pullwire blocks disposed onopposite sides of an abutment of the first drive nut, the first pullwireblock being disposed on a proximal side of the abutment with the firstpullwire extending distally from the first pullwire block, the secondpullwire block being disposed on a distal side of the abutment with thesecond pullwire extending proximally from the second pullwire block,wherein: the proximal translation of the first drive nut causes theabutment of the first drive nut to abut and push the first pullwireblock in a proximal direction, thereby causing the tension in the firstpullwire; and the distal translation of the first drive nut causes theabutment of the first drive nut to abut and push the second pullwireblock in a distal direction, thereby causing the tension in the secondpullwire.
 11. The steerable medical device of claim 10, comprising thirdand fourth pullwire blocks disposed on opposite sides of an abutment ofthe second drive nut, the third pullwire block being disposed on aproximal side of the abutment with the third pullwire extending distallyfrom the third pullwire block, the fourth pullwire block being disposedon a distal side of the abutment with the fourth pullwire extendingproximally from the fourth pullwire block, wherein: the proximaltranslation of the second drive nut causes the abutment of the seconddrive nut to abut and push the third pullwire block in a proximaldirection, thereby causing the tension in the third pullwire; and thedistal translation of the second drive nut causes the abutment of thesecond drive nut to abut and push the fourth pullwire block in a distaldirection, thereby causing the tension in the fourth pullwire.
 12. Asteerable medical device comprising: a handle including a longitudinalaxis; an elongate shaft extending distally from the handle, the elongateshaft including a distal tip and a lumen through the elongate shaft; atleast four pullwires disposed within the handle and extending to andanchored proximate the distal tip of the elongate shaft, the at leastfour pullwires including a first pullwire, a second pullwire, a thirdpullwire, and a fourth pullwire; at least two actuators associated withthe handle, the at least two actuators including a first actuator and asecond actuator, the at least two actuators being operably coupled tothe at least four pullwires, such that rotation of the first actuatorcauses tension in either the first pullwire or the second pullwire anddeflection of the distal tip in a first tip direction or a second tipdirection, respectively, and rotation of the second actuator causestension in either the third pullwire or the fourth pullwire anddeflection of the distal tip in a third tip direction or a fourth tipdirection, respectively; a support tube disposed within the handle androtationally and translationally constrained with respect to the handle,wherein the first and second actuators are operably coupled to thesupport tube, the second actuator being operably coupled to andtranslationally constrained by the support tube; a first threaded memberdisposed within the handle and rotatable with the rotation of the firstactuator in either the first actuator direction or the second actuatordirection, the first threaded member being operably coupled to the firstand second pullwires, wherein rotation of the first threaded membercauses the tension in at least one of the first pullwire and the secondpullwire, wherein the first threaded member is translationallyconstrained but rotatable within the handle, the first actuator beingoperably coupled to and translationally constrained by the firstthreaded member, such that the first and second actuators are eachindependently rotatable about the support tube and each constrained fromlongitudinal movement with respect to the support tube.
 13. Thesteerable medical device of claim 12, comprising a second threadedmember disposed within the handle and rotatable with the rotation of thesecond actuator in either the first actuator direction or the secondactuator direction, the second threaded member being operably coupled tothe third and fourth pullwires, wherein rotation of the second threadedmember causes the tension in at least one of the third pullwire and thefourth pullwire, wherein the second threaded member is translationallyconstrained but rotatable within the handle.
 14. The steerable medicaldevice of claim 13, wherein the first threaded member at least partiallyoverlaps the second threaded member, the second threaded member beingdisposed at least partially within the first threaded member, the firstand second threaded members being independently rotatable with respectto one another.
 15. The steerable medical device of claim 13, comprisinga first drive nut theadably coupled to the first threaded member, thefirst drive nut being rotationally constrained by the handle, the firstand second pullwires being operably coupled to the first drive nut,wherein the rotation of the first threaded member causes translation ofthe first drive nut along the longitudinal axis of the handle and, inturn, the tension in at least one of the first pullwire and the secondpullwire.
 16. The steerable medical device of claim 15, comprising asecond drive nut theadably coupled to the second threaded member, thesecond drive nut being rotationally constrained by the handle, the thirdand fourth pullwires being operably coupled to the second drive nut,wherein the rotation of the second threaded member causes thetranslation of the second drive nut along the longitudinal axis of thehandle and, in turn, the tension in at least one of the third pullwireand the fourth pullwire.
 17. The steerable medical device of claim 12,wherein: rotation of the first actuator in a first actuator directioncauses tension in the first pullwire and deflection of the distal tip inthe first tip direction; rotation of the first actuator in a secondactuator direction causes tension in the second pullwire and deflectionof the distal tip in the second tip direction substantially opposite thefirst tip direction; rotation of the second actuator in the firstactuator direction causes tension in the third pullwire and deflectionof the distal tip in the third tip direction different from the firsttip direction and the second tip direction; and rotation of the secondactuator in the second actuator direction causes tension in the fourthpullwire and deflection of the distal tip in the fourth tip directionsubstantially opposite the third tip direction.
 18. A steerable medicaldevice comprising: a handle including a longitudinal axis; an elongateshaft extending distally from the handle, the elongate shaft including adistal tip and a lumen through the elongate shaft; at least fourpullwires disposed within the handle and extending to and anchoredproximate the distal tip of the elongate shaft, the at least fourpullwires including a first pullwire, a second pullwire, a thirdpullwire, and a fourth pullwire; at least two actuators associated withthe handle, the at least two actuators including a first actuator and asecond actuator, the at least two actuators being operably coupled tothe at least four pullwires, such that rotation of the first actuatorcauses tension in either the first pullwire or the second pullwire anddeflection of the distal tip in a first tip direction or a second tipdirection, respectively, and rotation of the second actuator causestension in either the third pullwire or the fourth pullwire anddeflection of the distal tip in a third tip direction or a fourth tipdirection, respectively; at least two threaded members disposed withinthe handle, the at least two threaded members including a first threadedmember and a second threaded member, each of the first threaded memberand the second threaded member being translationally constrained butrotatable within the handle, the first threaded member being rotatablewith rotation of the first actuator, and the second threaded memberbeing rotatable with rotation of the second actuator, the first actuatorbeing operably coupled to and translationally constrained by the firstthreaded member; and a support tube disposed within the handle androtationally and translationally constrained with respect to the handle,wherein the first and second actuators are operably coupled to thesupport tube, the second actuator being operably coupled to andtranslationally constrained by the support tube, such that the first andsecond actuators are each independently rotatable about the support tubeand each constrained from longitudinal movement with respect to thesupport tube.
 19. The steerable medical device of claim 18, wherein thefirst threaded member at least partially overlaps the second threadedmember, the second threaded member being disposed at least partiallywithin the first threaded member, the first and second threaded membersbeing independently actuatable with respect to one another.
 20. Thesteerable medical device of claim 18, comprising at least two drive nutsdisposed within the handle, the at least two drive nuts including: afirst drive nut theadably coupled to the first threaded member, thefirst drive nut being rotationally constrained by the handle, the firstand second pullwires being operably coupled to the first drive nut,wherein the rotation of the first threaded member causes translation ofthe first drive nut along the longitudinal axis of the handle and, inturn, the tension in at least one of the first pullwire and the secondpullwire, and a second drive nut theadably coupled to the secondthreaded member, the second drive nut being rotationally constrained bythe handle, the third and fourth pullwires being operably coupled to thesecond drive nut, wherein the rotation of the second threaded membercauses the translation of the second drive nut along the longitudinalaxis of the handle and, in turn, the tension in at least one of thethird pullwire and the fourth pullwire.
 21. The steerable medical deviceof claim 18, wherein: rotation of the first actuator in a first actuatordirection causes tension in the first pullwire and deflection of thedistal tip in the first tip direction; rotation of the first actuator ina second actuator direction causes tension in the second pullwire anddeflection of the distal tip in the second tip direction substantiallyopposite the first tip direction; rotation of the second actuator in thefirst actuator direction causes tension in the third pullwire anddeflection of the distal tip in the third tip direction different fromthe first tip direction and the second tip direction; and rotation ofthe second actuator in the second actuator direction causes tension inthe fourth pullwire and deflection of the distal tip in the fourth tipdirection substantially opposite the third tip direction.